Assume That Investigators Crossed a Strain of Flies Carrying the Dominant

Multiple Choice

Assume that investigators crossed a strain of flies carrying the dominant eye mutation Lobe on the second chromosome with a strain homozygous for the second chromosome recessive mutations smooth abdomen and straw body.The F₁ Lobe females were then backcrossed with homozygous smooth abdomen,straw body males,the following phenotypes were observed: Give the map units between Lobe and straw.

A) 15
B) 7.5
C) 10
D) 20
E) 5